James Hornstein, M.D.
NPI 1629116587 · Family Medicine Physician · Ventura, CA
Enrolled with Medicare as Practitioner - Family Practice · source: CMS PECOS Public Provider Enrollment (2026.04.01)
James Hornstein, M.D. is a Family Medicine Physician provider in Ventura, CA (NPI 1629116587).
Provider details
- NPI number
- 1629116587
- Entity type
- Individual
- Primary specialty
- Family Medicine PhysicianAllopathic & Osteopathic Physicians
- Credential
- M.D.
- Sex
- Male
- Sole proprietor
- Yes
- License
- 770183168 (CA)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
19 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
2,352 Medicare services, 2024 (ranked within specialty)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our methodology.
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 566 | $97 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 558 | $136 |
| Chronic Care Management Services, First 20 Minutes of Clinical Staff Time Directed By Health Care Professional, Per Calendar Month99490 | 420 | $66 |
| Chronic Care Management Services for Two Or More Chronic Conditions, Additional 20 Minutes of Clinical Staff Time Directed By Health Care Professional, Per Calendar Month99439 | 211 | $51 |
| Telephone Medical Discussion With Physician, 11-20 Minutes99442 | 149 | $97 |
| Advance Care Planning, First 30 Minutes |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 72 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Losartan Potassium | 452 | 116 |
| Rosuvastatin Calcium | 362 | 103 |
| Atorvastatin Calcium | 246 | 72 |
| Levothyroxine Sodium | 203 | 51 |
| Hydrochlorothiazide | 141 | 39 |
| Metformin Hcl | 132 | 41 |
| Amlodipine Besylate |
Practice location
Mailing address
Registry dates
- Enumerated
- 2007-02-02
- Last updated
- 2015-03-23
Frequently asked questions
- What is James Hornstein's NPI number?
- James Hornstein's National Provider Identifier (NPI) is 1629116587, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is James Hornstein's specialty?
- James Hornstein is listed in the NPPES registry with a primary specialty of Family Medicine Physician (Allopathic & Osteopathic Physicians).
- Where is James Hornstein located?
- James Hornstein's practice location on file with NPPES is 2793 Loma Vista Rd, Ventura, CA 93003-1544.
- What is James Hornstein's phone number?
- The practice phone number listed in the NPPES registry for James Hornstein is (805) 643-9292.
- Does James Hornstein accept Medicare?
- James Hornstein is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is James Hornstein's NPI active?
- Yes — James Hornstein's NPI (1629116587) is active in the NPPES registry as of the last update on 2015-03-23.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.